Variable volume fluid distributor



March 5, 1963 R. L. ALLEN 3,079,948

VARIABLE VOLUME FLUID DISTRIBUTOR Filed Dec 19, 1957 FIG. 5

I INVENTOR. ROBERT L. ALLEN ATTORNEY liaise This invention relates to avariable volume fluid distributor, and is particularly concerned withdistributors for the feeding of variable volume liquid increments toindividual outlets from a single source. While the invention may findadmirable utility in a wide variety of mechanisms, it has been foundparticularly adaptable for the distribution of measured liquid fuelincrements in a fuel injection system for internal combustion engines.

in the development of fuel injection systems for multiple cylinder, highspeed, four cycle, internal combustion engines, many problems areencountered with respect to the distribution of individual accuratelymetered minute increments. in such systems, it is, of course,fundamental that the measured increments discharged must be accuratewithin fractions of droplets, and that such increments be delivered atsuch pressure and flow rate as to overcome inertia and friction in theline as well as resistance at the point of discharge. Since intimatedistribution of the fuel in the combustion supporting air is animportant factor in engine efficiency, jet nozzles are provided for thespray, diflusion or atomization of fuel as it is delivered. Consistentlyresponsive engine operation requires the delivery of fuel increments tothe nozzle at a discharge pressure faithfully within a range appropriateto the best operating conditions of the nozzle. Varying speed and loadconditions require varying fuel increment volumes, as well as variationsin the time sequence of increment injection.

Heretofore, efforts have been made to solve the problems inherent insuch high speed, variable volume feed of measured increments by thesimple expedient of high pressure. By the use of high pressures, it washoped that accurately measured, varying volume, increments would bedischarged at the rate required and with such force as ecessary;however, where such high pressures are resorted to, other problems areintroduced frequently in the nature of pounding, vapor-locks,turbulence, and pressure binds. Since the liquid fuel is substantiallynon-compressible, variable volumes at high pressure necessarily produceflow disturbances. Such disturbances inhibit the uniform and accuratedelivery of precisely measured vary ing volume increments at specifictime intervals and under desirable pressure conditions. The presentinvention provides a distributor by which the de 'red accurate,effective and efficient fuel distribution may be achieved without Iresort to high pressure. By the use of expansible chamber means,applicants distributor may be supplied with fuel in varying volumes, atlow pressure, for effective distribution in accurately measured variablevolume increments within a limited pressure range and without unduefluctuations, pounding, vapor-locks or turbulence. The pessure rangereferred to is such as to insure prompt fluid flow in discharge lines,overcoming frictional drag and inertia, as well as providing therequired pressure at the nozzle to insure the desired character of fuelatomization.

It is among the objects of the present invention to provide a novel,simple and improved fluid distributor for the incremental distributionof fluid from a single source.

A further object of the invention is to provide a distributor havingaccumulator means for receiving variable fluid volumes for distribution,thereby precluding excessive pressure build-up throughout the device andinsuring accurate volumetric output of the fluid.

Another object of the present invention is to provide means for insuringa rapid discharge of preselected increments of fluid in such manner asto overcome inertia rates hastens invests Patented Mar. 5, sees l g g gand friction lags from the distributor to associated mechanism.

it is also an object of the present invention to provide a distributorwhich, which simple in construction and operation, will properlyfunction to distribute small incremental portions of fluid, and onewhich while lending itself to economic manufacture is well adapted toprovide a long life of faithful operation.

Other objects of the invention include that of providing novel andimproved sealing arrangements for maintaining pressures within thedistributor as Well as insuring against loss of fluid, and to provide amechanism which any be easily assembled and disassembled.

Numerous other objects, features and advantages of the present inventionwill be apparent from consideration of the following specification,taken is conjunction with the accompanying drawings, in which:

FIG. 1 is a side elevation of one embodiment of the present invention.

FIG. 2 is a front elevation of that form of the device shown in FIG. 1.

FIG. 3 is an enlarged vertical cross section'taken on line 3-3 of KG. 2.

PEG. 4 is a reduced fragmentary cross section taken on line 4-4 of FIG.3.

FIG. 5 is an enlarged detail cross sectional View illustrating one ofthe accumulators in partially retracted position.

In that form of the invention here shown by way of example, thedistributor structure comprises a body 10 of octagonal configuration,the eight peripheral faces 11 of which are recessed as at 12 to receivetherein the bosses 14 of individual increment fluid outlet blocks 15.Each block if defines an elbow fluid discharge duct 16. The outer end ofeach duct 15 receives fluid distribution tube 17 while the inner end ofeach communicates with one of ei ht individual radial outlet ports 1% inthe body 19. The inner ends of the outlet ports 18 are in communicationwith the associated incremental fluid passages 19. Suitable 0 rings 2%}are applied as re uired.

One face of the body, here shown in FIG. 3 as on the right hand side, isformed with an annular marginal olfset 30 adapted to receive an annularshoulder 31 of a chamber forming housing 32. The housing 32 with thebody It defines a fuel chamber 33. Within the chamber 33 there ismounted a flow control member in the form of a rotary distributor disc34 which bears against the outer right hand face of the body it underinlet fluid pressure and yieldable spring tension. The disc 34 isprovided with a single distributor port 35', here shown as elongate andof arcuate form, its center of curvature coinciding with the center ofrotation of the disc 34*. The length or" the port 35 is less than thespacing between any two adjacent inlet ports of the passages 19, thusprecluding any possibility of simultaneous registration of port 35 withmore than one port 19. The disc 34- sealingly engages the right face ofthe body it} to preclude the flow of fluid from the chamber 33 to thesuccessive ducts except at such time as registration of the port 35occurs.

In the rotation of the disc 34 to successively register its port 35 withthe individual passages 19, there is of necessity an interruption ofuniform fluid flow. As the disc port moves from one passage 19 to thenext, fluid discharge is terminated, although fluid supply may beuniform. These discharge cut-offs are abrupt, rapid and positive, and inthe absence of yieldable compensating means for receiving fluid betweenthe discharge intervals, such as one or more accumulators as hereinafterreferred to, pressure build-up vibration and pounding will result indamage or the detriment of accuracy, efficiency and stability ofoperating characteristics.

The disc 34 is mounted for rotation by a drive shaft 3 40 through meansof a transverse key 41 seated withina transverse slot 42 at the innerend of the shaft 49. The key 41 is also received within a transverserecess 43 in the outer face of the disc 34. For urging the disc towardsealing engagement with the face of body 10, a counterbore 44 in theshaft 40 is provided with a spring 45 which encircles a stud 46 of thekey 41 and bears against the key to exert an inward pressure of the disc34 against the body. The outer face of the disc is subjected to .theinlet fuel pressure which assists in producing a sealing pressurewithout undue friction or galling.

Fluid is supplied to the distributor inlet chamber 33 through port 50 inthe housing 32 by supply pipe 51. Since the maintenance of pressurewithin a predetermined low range is essential to proper incrementaldistribution bythe rotation of the disc despite volume changes, pressureresponsive expansible chamber means are furnished. .In the presentconstruction, one such means comprises an accumulator communicating withthe inlet chamber 33. As here shown, this accumulator includes acup-shaped piston plunger 52 invertedly positioned within an accumulatorpiston bore 53 formed in the housing 32 and here arranged diametricallyopposite the inlet port 50. The chamber 53 communicates with the chamber33 by an accumulator port 54. The piston 52 is normally urged inwardlyin the bore 53 toward the port 54 by coil spring 55 confined by cap 56.The cap 56 is secured within a counterbore 57 encircling the piston bore53. At the inner end of the counterbore 57, a sealing O-ring 58 isprovided to preclude leakage of fluid past the outer walls of the piston52. By this arrangement, it will be seen that tvith the springadequately chosen to conform to the desired pressure within the chamber33 variable fluid volume will cause the piston 52 to be moved outwardlyin its cylin- 'der to compress the spring 55, thus maintaining saidpredetermined pressure throughout varying volumes. The accumulatorprovides for a reception of fluid exceeding the capacity of chamber 33,thus increased fluid supply will not cause an increase of pressurebeyond a prescribed range, the spring pressure on the accumulator pistondetermining the optimum of such range.

Under certain circumstances and in certain equipment, it may well bethat additional accumulator means could be profitably employed topreclude excessive pressure and to efiect the adequate delivery of fluidand/or to insure the rapid passage of fluid despite friction losses andinertia of liquid in the delivery tubes 17. Where the fluid is to bedischarged through injection nozzles in which spring restrained orificeclosures are employed, some modifying eifect on fluid flow, vibrationand pressure may be achieved. However, in the absence of an establishedrelationship between a primary accumulator pressure and nozzle flowresistance, or where other factors of pressure, flow, volume and cut-ofienter, individual discharge line accumulators may be advisable.Therefore, in the present form of the invention each duct 19 is providedwith an individual accumulator here shown as similar in form to theaccumulator associated with the inlet chamber 33. For this purpose, eachduct 19 extends transversely through the body outward to the individualaccumulator chamber 60 in which cup-like accumulator pistons 61 aremounted for reciprocation against the pressure of the springs 62. A cap63 is provided for each piston 61 to retain'its spring 62 in position.o-rings 64 are mounted in the counterbores 65 which receive the innerends of the caps. For retaining all of the caps in assembled relationthere is provided a spider 70, the eight terminal finger ends 71 ofwhich rest against the eight outer faces 72 of the caps. The head 73 ofa bolt 74 retains the spider in position, adequately spaced by anintervening cylindrical spacer 75. As hereinbefore mentioned, successfuloperation of the device has shown the single accumulator of housing 32to be adequate; however, either or both of the accumulator arrangementsmay be used.

From the foregoing it will be seen that as" fluid is sup plied by thepipe 51 through port 50 to the supply chamber 33, such fluid will besubjected to the action of the accumulator spring to establish andmaintain a predetermined pressure. Such fluid will urge the pistonoutwardly against the spring to maintain such pressure despite possiblefluctuations of inlet pressure or changes in the rate of flow of fluidsupplied. Thus the accumulator will permit variations in fluid supplywithout substantial pressure variation, so that the engine may besupplied by various increment volumes without change in fluid pressure.As the disc 34 is rotated, the port 35 will successively register withthe ports of the duct 19 to successively admit an incremental pulse offluid from the chamber 33 to the successive ducts 19. It will, ofcourse, be noted that the outer free face of the disc 34 is subjected tothe substantially uniform pressure of the fluid in chamber 3-3, hencesuch pressure will assist spring 45 in sealingly retaining the disc overthe ports 19. Such pressure, how ever, being limited by the accumulatorwill not bind or gall the disc. As the fluid is received by theducts'19, the individual accumulators 6b to 68 will provide for amaintenance of the pressure at which the fluid is delivered andfor anappropriate incremental supply to each tube 17.

It will be noted that in the movement of the disc aper ture 35 betweenports 19, a positive termination of discharge flow is abruptly eifected.Since the fluid supply can rarely if ever be so regulated as to conformwith any such rapid and positive pulsations of discharge, excessivepressures of disasterous magnitude could be built up in the absence ofcompensating means in the nature of the present accumulator forreceiving and storing the marginal fluid delivered during the interimbetween'fluid discharges. Not only does the accumulator receive thefluid volume supplied between incremental discharges, which volumevaries as the engine demand for fuel varies, but such re.- ception isunder a sustained pressure operable to deliver such received fluid atthe prescribed pressure upon the advent of the next discharge phase.Thus the present structure implements a new concept in high speed,.lowpressure, incremental fluid delivery, a substantially constant pressurewithin a predeterinmed range being achieved by the periodic storage ofoverlapping supply in crements under controlled pressure conditionsbetween the discharge intervals.

It will be noted that the structure and arrangeemnt is simple,eflicient, and effective, well designed to meet the demands of economicmanufacture, formed to withstand the speeds appropriate for fuelinejction systems, and which may be readily disassembled and reassembledfor maintenance, service and cleaning or repairs. In the practice of theinvention it will be'understood that numerous changes, modifications andthe full use of equivalents may be resorted to without departure fromthe spirit or scope of the invention as defined in the appended claims.

I claim:

1. A fluid distributor for lthe'delivery of a plurality of separatesuccessive pulses of fluid increments to separate discharge linesincluding means defining a fluid chamber, a fluid inlet to said chamber,a rotatable disc defining a single fluid outlet from said chamber, aplurality of individual fluid outlet ports successively registrable withthe fluid outlet of said disc, and pressure responsive means formaintaining substantially uniform pressure of fluid discharged throughsaid individual fluid outlet ports, said pressure responsive meansincluding individual accumulators associated with each individual outletport and biased to maintain substantially uniform pressure aboveapredetermined minimum and for discharging the accumulated fluid priorrto the delivery thereto of its next increment.

outlets communicating with separate discharge lines, a rotatable discdefining a single fluid passage successively registrable with said fluidoutlets, and pressure responsive means for maintaining substantiallyuniform fluid pressure in said distributor, said pressure responsivemeans including a single expansible chamber accumulator constantlycommunicating with said inlet, and individual expansible chamberaccumulators directly communicating with said individual outlets andbiased to maintain substantially uniform pressure above a predeterminedminimumand for discharging the accumulated fluid prior to the deliverythereto of its next increment.

3. A distributor for the fuel injection system of a multicylinderinternal combustion engine wherein variable volumes of incrementalpulses of fuel are injected to the cylinders of the engine, including abody, a circul-ar series of individual fuel increment outlet portsdefined by said body, a housing cooperating with said body to form afluid chamber, a fuel inlet for said chamher, a rotatable disc defininga fuel outlet from said chamber, lthe wis of rotation of said disc beingconcentric with the axis of said circular series of individual fuelincrement outlet port-s, said disc defined outlet being elongate and ofa length less than the spacing between adjacent fuel increment outletsin said circular series, and means for urging said disc toward saidbody, together with means for maintaining uniform fluid pressure in saiddistributor during discharge of said variable volumes, said meansincluding an exp ansible chamber accumulator constantly communicatingwith said chamber and a plurality of expansi-ble chamber accumulatorscommunicating respectively with said individual outlet ports, saidaccumulator in communication with said chamber being biased to maintainsubstantially uniform pressure above a predetermined minimum between thedelivery of one such increment and the next and for discharging theaccumulated fluid during the delivery of said next increment.

4. A fluid distributor periodically delivering separate increments offluid from a single fluid supply which may vary independently ofvariations of the time between the delivery of one such increment andthe next, said distributor defining a fluid supply chamber together witha fluid supply duct and a fluid discharge duct, means movable in saidchamber to periodically deliver fluid increments from said chamber tosaid discharge duct, and means in constant communication with saidchamber for accommodating variable volumes of fluid at uniform pressurewithin said chamber, said means including a pressure responsive variabledisplacement accumulator biased to maintain substantially uniformpressure above a selected minim-um, below which said accumulator isinoperative to receive fluid, between the delivery of one such incrementand the next and for discharging the accumulated fluid during thedelivery of said next increment.

5. A fluid distributor periodically delivering separate increments offluid from a fluid supply which may vary independently of variations ofthe time between the delivery of one such increment and the next, saiddistributor defining a fluid supply chamber, a fluid inlet to saidchamber and a fluid outlet from said chamber, means movable in saidchamber to periodically deliver increments of fluid from said chamber tosaid fluid outlet, and means for varying the effective capacity of saidchamber, said last mentioned means including a pressure responsive fluidaccumulator in constant communication with said inlet and biased tomaintain substantially uniform pressure above a selected minimum, belowwhich said accumulator is inoperative to receive fluid, from between thedelivery of one such increment and the next and for discharging theaccumulated fluid during the delivery of said next increment.

6. In a distributor having a chamber, means for discharging liquid fromsaid chamber as spaced intervals, means for constantly delivering liquidto said chamber in quantity which may vary independently of variationsin the time between such intervals, and yieldable means foraccommodating the supply of liquid between said intervals of dischargeso as to maintain the fluid pressure in said chamber substantiallyconstant above a selected minimum, below which said accumulator isinoperative to receive fluid, between the discharge at one interval andthe next and for discharging the accommodated liquid during thedischarge at said next interval.

7. A fluid distributor for the timed delivery of fluid incrementscomprising a supply chamber for fluid, a distributor member having asurface with a plurality of annularly disposed and circumferentiallyspaced delivery ports, a distributor plate between said supply chamberand said surface and having a release port to successively register withsaid delivery ports upon the rotation of said plate, said release portbeing of a maximum circumferential dimension to prevent simultaneousopening of any two adjacent ports, means for delivering fluid to saidsupply chamber in quantity which may vary independently of the speed ofrotation of said distributor plate, an accumulator chamber having amovable wall, and biasing means for urging said wall in a direction toreduce the size of said accumulator chamber, said wall and said biasingmeans having a frequency response sufl'iciently great to follow pressurechanges in said supply chamber for maintaining substantially uniformpressure above a selected minimum pressure, below which said accumulatoris inoperative to receive fluid, between the registering of said releaseport with any one of said delivery ports and the next adjacent port andfor reducing the size of said chamber to a predetermined minimum uponregistration of said release port with said next adjacent port.

References Cited in the file of this patent UNITED STATES PATENTS1,094,097 Pouley Apr. 21, 1914 1,737,389 Redmond Nov. 26, 1929 1,968,390Hamilton July 31, 1934 2,300,722 Adams Nov. 3, 1942 2,632,458 SlomerMar. 24, 1953 2,720,344 Isreeli Oct. 11, 1955 2,750,933 Lauck June 19,1956 FOREIGN PATENTS 152,959 Sweden Jan. 3, 1956 857,523 France Apr. 22,1940

1. A FLUID DISTRIBUTOR FOR THE DELIVERY OF A PLURALITY OF SEPARATESUCCESSIVE PULSES OF FLUID INCREMENTS TO SEPARATE DISCHARGE LINESINCLUDING MEANS DEFINING A FLUID CHAMBER, A FLUID INLET TO SAID CHAMBER,A ROTATABLE DISC DEFINING A SINGLE FLUID OUTLET FROM SAID CHAMBER, APLURALITY OF INDIVIDUAL FLUID OUTLET PORTS SUCCESSIVELY REGISTRABLE WITHTHE FLUID OUTLET OF SAID DISC, AND PRESSURE RESPONSIVE MEANS FORMAINTAINING SUBSTANTIALLY UNIFORM PRESSURE OF FLUID DISCHARGED THROUGHSAID INDIVIDUAL FLUID OUTLET PORTS, SAID PRESSURE RESPONSIVE MEANSINCLUDING INDIVIDUAL ACCUMULATORS ASSOCIATED WITH EACH INDIVIDUAL OUTLETPORT AND BIASED TO MAINTAIN SUBSTANTIALLY UNIFORM PRESSURE ABOVE APREDETERMINED MINIMUM AND FOR DISCHARGING THE ACCUMULATED FLUID PRIOR TOTHE DELIVERY THERETO OF ITS NEXT INCREMENT.